The present invention pertains to a rotary cutting tool for removing material from a workpiece. More specifically, the present invention pertains to a rotary cutting tool such as, for example, an end mill, for removing material from a workpiece wherein a single rotary cutting tool carries out a roughing operation and a finishing operation. Even more specifically, the present invention pertains to a rotary cutting tool such as, for example, an end mill, for removing material from a workpiece wherein a single rotary cutting tool, which has a plurality blades wherein each blade has a finishing cutting edge portion and a roughing cutting edge portion so that the single rotary cutting tool carries out the roughing operation and the finishing operation.
Rotary cutting tools such as, for example, an end mill, are used for cutting many types of materials, from metals to plastics. Rotary cutting tools are supported by a shank which is generally cylindrical and adapted to be removably gripped by a motor driven chuck or functionally similar device. The shank graduates into a cutting portion on a single-end end mill or into two cutting portions on a double-end end mill. The cutting portion extends to an end of the end mill. The cutting portion has a plurality of cutting blades which are separated by flutes for carrying away the chips of the workpiece material which are generated by the cutting operation. The cutting blades and the flutes may be parallel to the end mill's longitudinal axis, but more often are helical. The cutting portion typically terminates with radial cutting features designed to complement the cutting action provided by the axial portions of the cutting blades. Generally, rotary cutting tools, (e.g., end mills) are used in milling applications such as, for example and without limitation, profile milling, tracer milling, face milling, and plunging. Rotary cutting tools can be used to remove material from workpiece materials such as, for example, stainless steels, high-temperature steels and aluminum alloys.
Heretofore, many end mills do not have the capability to rough and finish using the same end mill. Therefore, it would be highly desirable to provide a rotary cutting tool (e.g., end mill) that can rough and finish using the same end mill tool. Even though some end mills operate so as to perform a roughing and finishing operation, such end mills exhibit a straight cutting edge or a chip breaker form (for roughing) which is continuous on any one blade. These end mills do not use a true roughing form and a straight finishing form on a single cutting edge. Further, these end mills do not use a roughing cutting portion and a finishing portion that are overlapping and staggered with reference to the adjacent blade. Therefore, it would be highly desirable to provide a rotary cutting tool that has a roughing cutting portion and finishing cutting portion on the same blade. It would also be highly desirable to provide a rotary cutting tool that has a plurality of blades wherein each blade a roughing cutting portion and finishing cutting portion and wherein the roughing cutting portion and finishing cutting portion of adjacent blades overlap. Such a rotary cutting tool reduces the torque (and the horsepower consumption) necessary to properly function due to the overlapping dual profile cutting edges.
While end mills in the past exhibit both axial and radial engagement with the workpiece, there remains a need to improve such engagement. Therefore, it would be highly desirable to provide a rotary cutting tool that can increase both axial and radial engagement due to the rougher profile of the cutting edge and exhibit more aggressive overall cutting characteristics.
Earlier end mills have operated in a satisfactory manner; however, there remains a need to improve the operation of such end mills. Therefore, it would be highly desirable to provide a rotary cutting tool that can reduce the tool deflection during operation which then allows for greater feeding rates.
It would also be highly desirable to provide a rotary cutting tool that can better break chips that results in the better evacuation of the chips then has heretofore been available. It would be highly desirable to provide a rotary cutting tool that reduces the harmonics which occur in long wall applications. It would be highly desirable to provide a rotary cutting tool that cuts with heavier feeds using less horsepower and leaves a finished surface on the workpiece.